They. Were. Inside. A. Car.
If they were truly car blocked by the woman or her daughter, then calling the police would be sufficient. The family was unarmed and simply asking for an apology. If they crossed a line and actually did block the car's exit, that's a breach of etiquette and decorum, not a mortal threat.
I cannot see any evidence they were car blocked, however, so what then would be the obstacle to just driving away? Again -- what was the threat that required pointing a gun?
There's really no way you can make the gun-wielding Karen come off as a rational adult.